1. Field of the Invention
The instant disclosure relates to a SMD type Fresnel LED micro flash light structure, which can be used in a camera or portable electronic device with the photographic function, such as a camera of a mobile phone; in particular, to a Fresnel flashlight structure having at least two LEDs with Fresnel lens of technology art of photograph.
2. Description of Related Art
Since electronic products have developed rapidly, many portable electronic devices are equipped with a camera and LED flashlight. The LED flashlight usually consists of a single or many LEDs. To conform to luminous flux and slim structure design, the Fresnel lens with light and thin characteristics has been widely applied in LED flashlight. The conventional Fresnel lens is usually circular shaped or oval-shaped, and its surface is formed of at least one set of a Fresnel zone plate with a complicated appearance.
With the increased high pixels of the camera and better photographic effect, the single LED light combined with the single Fresnel zone plate produces an oval-shaped illumination pattern and is not fit enough. As shown in FIG. 5, a conventional Fresnel lens 9 consists of two circular-shaped or oval-shaped Fresnel zone plates 91, 92, and two LEDs lights. The illumination patterns, which are produced by the Fresnel lens 9 after overlap, are usually in an 8-shape. The illumination effect at two sides of the middle portion is not uniform, and the difference between the minimum luminous intensity and highest luminous intensity is great. Therefore, the light emitted to the photograph objective cannot provide uniform illumination, and this affects the quality of the photograph. It is desired to solve the aforesaid problems of how to properly condense the light in a desired illumination pattern within the limitation of finite LED light sources.